Aryl, heteroaryl or vinyl halides can be trifluoromethylated using CF3CO2Na-Cul. With alkyl iodides, however, the method fails, yielding trifluoroacetyl esters instead. Allylic halogens can be substituted with Burton's reagent, obtained from dihalogenodifluoromethane via CF3CdHal and transmetallation with Cul. A new access to trifluoropropionic acid is thereby found. Prop-2-ynyl bromide produces trifluoromethylallene. Attempts at trifluoromethylation of bromoacetate with CF3CO2Na-Cul in NMP (N-methyl-2-pyrrolidone) solution led to formation of the trifluoroacetoxy derivative and of a formal adduct of hexafluoroacetone to the alpha-position of NMP.